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Ahmed MMA, Boudreau PD. LCMS-Metabolomic Profiling and Genome Mining of Delftia lacustris DSM 21246 Revealed Lipophilic Delftibactin Metallophores. JOURNAL OF NATURAL PRODUCTS 2024; 87:1384-1393. [PMID: 38739531 DOI: 10.1021/acs.jnatprod.4c00049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Bacteria have evolved various strategies to combat heavy metal stress, including the secretion of small molecules, known as metallophores. These molecules hold a potential role in the mitigation of toxic metal contamination from the environment (bioremediation). Herein, we employed combined comparative metabolomic and genomic analyses to study the metallophores excreted by Delftia lacustris DSM 21246. LCMS-metabolomic analysis of this bacterium cultured under iron limitation led to a suite of lipophilic metallophores exclusively secreted in response to iron starvation. Additionally, we conducted genome sequencing of the DSM 21246 strain using nanopore sequencing technology and employed antiSMASH to mine the genome, leading to the identification of a biosynthetic gene cluster (BGC) matching the known BGC responsible for delftibactin A production. The isolated suite of amphiphilic metallophores, termed delftibactins C-F (1-4), was characterized using various chromatographic, spectroscopic, and bioinformatic techniques. The planar structure of these compounds was elucidated through 1D and 2D NMR analyses, as well as LCMS/MS-based fragmentation studies. Notably, their structures differed from previously known delftibactins due to the presence of a lipid tail. Marfey's and bioinformatic analyses were employed to determine the absolute configuration of the peptide scaffold. Delftibactin A, a previously identified metallophore, has exhibited a gold biomineralizing property; compound 1 was tested for and also demonstrated this property.
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Affiliation(s)
- Mohammed M A Ahmed
- Boudreau Lab, Department of BioMolecular Science, School of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
- Department of Pharmacognosy, Al-Azhar University, Cairo 11651, Egypt
| | - Paul D Boudreau
- Boudreau Lab, Department of BioMolecular Science, School of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
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2
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Sengupta S, Pabbaraja S, Mehta G. Natural products from the human microbiome: an emergent frontier in organic synthesis and drug discovery. Org Biomol Chem 2024; 22:4006-4030. [PMID: 38669195 DOI: 10.1039/d4ob00236a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024]
Abstract
Often referred to as the "second genome", the human microbiome is at the epicenter of complex inter-habitat biochemical networks like the "gut-brain axis", which has emerged as a significant determinant of cognition, overall health and well-being, as well as resistance to antibiotics and susceptibility to diseases. As part of a broader understanding of the nexus between the human microbiome, diseases and microbial interactions, whether encoded secondary metabolites (natural products) play crucial signalling roles has been the subject of intense scrutiny in the recent past. A major focus of these activities involves harvesting the genomic potential of the human microbiome via bioinformatics guided genome mining and culturomics. Through these efforts, an impressive number of structurally intriguing antibiotics, with enhanced chemical diversity vis-à-vis conventional antibiotics have been isolated from human commensal bacteria, thereby generating considerable interest in their total synthesis and expanding their therapeutic space for drug discovery. These developments augur well for the discovery of new drugs and antibiotics, particularly in the context of challenges posed by mycobacterial resistance and emerging new diseases. The current landscape of various synthetic campaigns and drug discovery initiatives on antibacterial natural products from the human microbiome is captured in this review with an intent to stimulate further activities in this interdisciplinary arena among the new generation.
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Affiliation(s)
- Saumitra Sengupta
- School of Chemistry, University of Hyderabad, Hyderabad-500046, India.
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad-500007, India
| | - Srihari Pabbaraja
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad-500007, India
- Academy of Scientific & Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Goverdhan Mehta
- School of Chemistry, University of Hyderabad, Hyderabad-500046, India.
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3
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Andriyanov PA, Kashina DD, Menshikova AN. Genomic analysis of multidrug-resistant Delftia tsuruhatensis isolated from raw bovine milk. Front Microbiol 2024; 14:1321122. [PMID: 38239723 PMCID: PMC10794605 DOI: 10.3389/fmicb.2023.1321122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/06/2023] [Indexed: 01/22/2024] Open
Abstract
Delftia tsuruhatensis is a gram-negative, aerobic bacterium mostly known as an organic pollutant degrading and growth-promoting microorganism. However, it recently emerged as an opportunistic human pathogen. To date, the source of D. tsuruhatensis infection is not clear. The majority of studies of D. tsuruhatensis have focused on environmental or clinical strains, while investigations of D. tsuruhatensis strains isolated from food sources are limited. In the present study, we report the case of D. tsuruhatensis isolation from raw bovine milk. Classical bacteriology approaches, as well as next-generation sequencing and comparative genomics, were used to characterize the features of the D. tsuruhatensis MR-6/3H strain. The MR-6/3H strain was resistant to 19 antimicrobials among 23 tested, including all aminoglycosides, phenicol, trimethoprim-sulfamethoxazole, and almost all β-lactams. Phylogenetically, the MR-6/3H was close to clinical origin strains, including those previously isolated in Russia. Comparative genomics revealed the presence of putative antimicrobial resistance genes in the MR-6/3H isolate, mostly associated with efflux systems. Notably, genus-specific OXA-926-like β-lactamase was also detected. In all, 27 putative virulence factors were predicted, the majority of which were associated with motility, adherence, stress survival, siderophore synthesis, and immunomodulation. In the MR-6/3H genome, the five prophage regions were identified, including two with intact levels. Integrons and CRISPR-Cas systems were not detected in the MR-6/3H isolate. Thus, our findings suggest that raw milk can be the potential source of and transmission route for the dissemination of multidrug-resistant D. tsuruhatensis.
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Affiliation(s)
- Pavel A. Andriyanov
- Federal Research Center for Virology and Microbiology, Branch in Nizhny Novgorod, Nizhny Novgorod, Russia
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4
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Rangel K, Lechuga GC, Provance DW, Morel CM, De Simone SG. An Update on the Therapeutic Potential of Antimicrobial Peptides against Acinetobacter baumannii Infections. Pharmaceuticals (Basel) 2023; 16:1281. [PMID: 37765087 PMCID: PMC10537560 DOI: 10.3390/ph16091281] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 08/09/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
The rise in antibiotic-resistant strains of clinically important pathogens is a major threat to global health. The World Health Organization (WHO) has recognized the urgent need to develop alternative treatments to address the growing list of priority pathogens. Antimicrobial peptides (AMPs) rank among the suggested options with proven activity and high potential to be developed into effective drugs. Many AMPs are naturally produced by living organisms protecting the host against pathogens as a part of their innate immunity. Mechanisms associated with AMP actions include cell membrane disruption, cell wall weakening, protein synthesis inhibition, and interference in nucleic acid dynamics, inducing apoptosis and necrosis. Acinetobacter baumannii is a critical pathogen, as severe clinical implications have developed from isolates resistant to current antibiotic treatments and conventional control procedures, such as UV light, disinfectants, and drying. Here, we review the natural AMPs representing primary candidates for new anti-A. baumannii drugs in post-antibiotic-era and present computational tools to develop the next generation of AMPs with greater microbicidal activity and reduced toxicity.
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Affiliation(s)
- Karyne Rangel
- Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation in Neglected Population Diseases (INCT-IDPN), Oswaldo Cruz Institut, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, RJ, Brazil; (K.R.); (G.C.L.); (D.W.P.J.); (C.M.M.)
- Epidemiology and Molecular Systematics Laboratory (LEMS), Oswaldo Cruz Institut, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, RJ, Brazil
| | - Guilherme Curty Lechuga
- Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation in Neglected Population Diseases (INCT-IDPN), Oswaldo Cruz Institut, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, RJ, Brazil; (K.R.); (G.C.L.); (D.W.P.J.); (C.M.M.)
- Epidemiology and Molecular Systematics Laboratory (LEMS), Oswaldo Cruz Institut, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, RJ, Brazil
| | - David W. Provance
- Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation in Neglected Population Diseases (INCT-IDPN), Oswaldo Cruz Institut, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, RJ, Brazil; (K.R.); (G.C.L.); (D.W.P.J.); (C.M.M.)
- Epidemiology and Molecular Systematics Laboratory (LEMS), Oswaldo Cruz Institut, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, RJ, Brazil
| | - Carlos M. Morel
- Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation in Neglected Population Diseases (INCT-IDPN), Oswaldo Cruz Institut, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, RJ, Brazil; (K.R.); (G.C.L.); (D.W.P.J.); (C.M.M.)
| | - Salvatore G. De Simone
- Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation in Neglected Population Diseases (INCT-IDPN), Oswaldo Cruz Institut, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, RJ, Brazil; (K.R.); (G.C.L.); (D.W.P.J.); (C.M.M.)
- Epidemiology and Molecular Systematics Laboratory (LEMS), Oswaldo Cruz Institut, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, RJ, Brazil
- Program of Post-Graduation on Science and Biotechnology, Department of Molecular and Cellular Biology, Biology Institute, Federal Fluminense University, Niterói 22040-036, RJ, Brazil
- Program of Post-Graduation on Parasitic Biology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, RJ, Brazil
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5
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Pisco-Ortiz C, González-Almario A, Uribe-Gutiérrez L, Soto-Suárez M, Amaya-Gómez CV. Suppression of tomato wilt by cell-free supernatants of Acinetobacter baumannii isolates from wild cacao from the Colombian Amazon. World J Microbiol Biotechnol 2023; 39:297. [PMID: 37658991 PMCID: PMC10475004 DOI: 10.1007/s11274-023-03719-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/01/2023] [Indexed: 09/05/2023]
Abstract
Tomato vascular wilt caused by Fusarium oxysporum f. sp. lycopersici (Fol) is one of the most limiting diseases of this crop. The use of fungicides and varieties resistant to the pathogen has not provided adequate control of the disease. In this study, siderophore-producing bacteria isolated from wild cocoa trees from the Colombian Amazon were characterized to identify prominent strategies for plant protection. The isolates were taxonomically classified into five different genera. Eight of the fourteen were identified as bacteria of the Acinetobacter baumannii complex. Isolates CBIO024, CBIO086, CBIO117, CBIO123, and CBIO159 belonging to this complex showed the highest efficiency in siderophore synthesis, producing these molecules in a range of 91-129 µmol/L deferoxamine mesylate equivalents. A reduction in disease severity of up to 45% was obtained when plants were pretreated with CBIO117 siderophore-rich cell-free supernatant (SodSid). Regarding the mechanism of action that caused antagonistic activity against Fol, it was found that plants infected only with Fol and plants pretreated with SodSid CBIO117 and infected with Fol showed higher levels of PR1 and ERF1 gene expression than control plants. In contrast, MYC2 gene expression was not induced by the SodSid CBIO117 application. However, it was upregulated in plants infected with Fol and plants pretreated with SodSid CBIO117 and infected with the pathogen. In addition to the disease suppression exerted by SodSid CBIO117, the results suggest that the mechanism underlying this effect is related to an induction of systemic defense through the salicylic acid, ethylene, and priming defense via the jasmonic acid pathway.
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Affiliation(s)
- Carolina Pisco-Ortiz
- Centro de Investigación La Libertad, Corporación Colombiana de Investigación Agropecuaria - Agrosavia, Villavicencio, Meta, Colombia
| | | | - Liz Uribe-Gutiérrez
- Centro de investigación Tibaitatá, Corporación Colombiana de Investigación Agropecuaria-Agrosavia, Mosquera, Cundinamarca, Colombia
| | - Mauricio Soto-Suárez
- Centro de investigación Tibaitatá, Corporación Colombiana de Investigación Agropecuaria-Agrosavia, Mosquera, Cundinamarca, Colombia
| | - Carol V Amaya-Gómez
- Centro de Investigación La Libertad, Corporación Colombiana de Investigación Agropecuaria - Agrosavia, Villavicencio, Meta, Colombia.
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6
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Amin DH, Nageeb WM, Elkelish A, Makharita RR. Mining metagenomes reveals diverse antibiotic biosynthetic genes in uncultured microbial communities. Braz J Microbiol 2023:10.1007/s42770-023-00953-z. [PMID: 36977970 DOI: 10.1007/s42770-023-00953-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 03/11/2023] [Indexed: 03/30/2023] Open
Abstract
Pathogens resistant to antimicrobials form a significant threat to public health worldwide. Tackling multidrug-resistant pathogens via screening metagenomic libraries has become a common approach for the discovery of new antibiotics from uncultured microorganisms. This study focuses on capturing nonribosomal peptide synthase (NRPS) gene clusters implicated in the synthesis of many natural compounds of industrial relevance. A NRPS PCR assay was used to screen 2976 Escherichia coli clones in a soil metagenomic library to target NRPS genes. DNA extracts from 4 clones were sequenced and subjected to bioinformatic analysis to identify NRPS domains, their phylogeny, and substrate specificity.Successfully, 17 NRPS-positive hits with a biosynthetic potential were identified. DNA sequencing and BLAST analysis confirmed that NRPS protein sequences shared similarities with members of the genus Delftia in the Proteobacteria taxonomic position. Multiple alignment and phylogenetic analysis demonstrated that clones no. 15cd35 and 15cd37 shared low bootstrap values (54%) and were distantly far from close phylogenetic neighbors. Additionally, NRPS domain substrate specificity has no hits with the known ones; hence, they are more likely to use different substrates to produce new diverse antimicrobials. Further analysis confirmed that the NRPS hits resemble several transposon elements from other bacterial taxa, confirming its diversity. We confirmed that the analyses of the soil metagenomic library revealed a diverse set of NRPS related to the genus Delftia. An in-depth understanding of those positive NRPS hits is a crucial step for genetic manipulation of NRPS, shedding light on alternative novel antimicrobial compounds that can be used in drug discovery and hence supports the pharmaceutical sector.
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Affiliation(s)
- Dina H Amin
- Microbiology Department, Faculty of Science, Ain Shams University, Cairo, 11566, Egypt.
| | - Wedad M Nageeb
- Medical Microbiology and Immunology Department, Faculty of Medicine, Suez Canal University, Ismailia, 41111, Egypt
| | - Amr Elkelish
- Biology Department, College of Science, Imam Mohammad ibn Saud Islamic University (IMSIU), 90950, Riyadh, 11623, Saudi Arabia
- Botany and Microbiology Department, Faculty of Science, Suez Canal University, Ismailia, 41522, Egypt
| | - Rabab R Makharita
- Department of Biology, College of Sciences and Arts, Khulis, University of Jeddah, Jeddah, 21959, Saudi Arabia
- Botany and Microbiology Department, Faculty of Science, Suez Canal University, Ismailia, 41522, Egypt
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7
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Genome Sequences of Two Soil-Dwelling Bacteria Belonging to the Family
Comamonadaceae. Microbiol Resour Announc 2022; 11:e0023022. [PMID: 35997499 PMCID: PMC9476982 DOI: 10.1128/mra.00230-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Members of the family Comamonadaceae are rod-shaped betaproteobacteria found in various environments. Here, we report the genome sequences of 2 bacteria belonging to this family. They were isolated from agricultural soils located in the Montérégie region (Quebec, Canada) and display biocontrol activity against various lettuce bacterial pathogens.
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Pan-Genome Analysis of Delftia tsuruhatensis Reveals Important Traits Concerning the Genetic Diversity, Pathogenicity, and Biotechnological Properties of the Species. Microbiol Spectr 2022; 10:e0207221. [PMID: 35230132 PMCID: PMC9045143 DOI: 10.1128/spectrum.02072-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Delftia tsuruhatensis strains have long been known to promote plant growth and biological control. Recently, it has become an emerging opportunistic pathogen in humans. However, the genomic characteristics of the genetic diversity, pathogenicity, and biotechnological properties have not yet been comprehensively investigated. Here, a comparative pan-genome analysis was constructed. The open pan-genome with a large and flexible gene repertoire exhibited a high degree of genetic diversity. The purifying selection was the main force to drive pan-genome evolution. Significant differences were observed in the evolutionary relationship, functional enrichment, and degree of selective pressure between the different components of the pan-genome. A high degree of genetic plasticity was characterized by the determinations of diverse mobile genetic elements (MGEs), massive genomic rearrangement, and horizontal genes. Horizontal gene transfer (HGT) plays an important role in the genetic diversity of this bacterium and the formation of genomic traits. Our results revealed the occurrence of diverse virulence-related elements associated with macromolecular secretion systems, virulence factors associated with multiple nosocomial infections, and antimicrobial resistance, indicating the pathogenic potential. Lateral flagellum, T1SS, T2SS, T6SS, Tad pilus, type IV pilus, and a part of virulence-related genes exhibited general properties, whereas polar flagellum, T4SS, a part of virulence-related genes, and resistance genes presented heterogeneous properties. The pan-genome also harbors abundant genetic traits related to secondary metabolism, carbohydrate active enzymes (CAZymes), and phosphate transporter, indicating rhizosphere adaptation, plant growth promotion, and great potential uses in agriculture and biological control. This study provides comprehensive insights into this uncommon species from the genomic perspective. IMPORTANCED. tsuruhatensis is considered a plant growth-promoting rhizobacterium (PGPR), an organic pollutant degradation strain, and an emerging opportunistic pathogen to the human. However, the genetic diversity, the evolutionary dynamics, and the genetic basis of these remarkable traits are still little known. We constructed a pan-genome analysis for D. tsuruhatensis and revealed extensive genetic diversity and genetic plasticity exhibited by open pan-genome, diverse mobile genetic elements (MGEs), genomic rearrangement, and horizontal genes. Our results highlight that horizontal gene transfer (HGT) and purifying selection are important forces in D. tsuruhatensis genetic evolution. The abundant virulence-related elements associated with macromolecular secretion systems, virulence factors, and antimicrobial resistance could contribute to the pathogenicity of this bacterium. Therefore, clinical microbiologists need to be aware of D. tsuruhatensis as an opportunistic pathogen. The genetic profiles of secondary metabolism, carbohydrate active enzymes (CAZymes), and phosphate transporter could provide insight into the genetic armory of potential applications for agriculture and biological control of D. tsuruhatensis in general.
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Barber CC, Zhang W. Small molecule natural products in human nasal/oral microbiota. J Ind Microbiol Biotechnol 2021; 48:6129854. [PMID: 33945611 PMCID: PMC8210680 DOI: 10.1093/jimb/kuab010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 12/07/2020] [Indexed: 12/26/2022]
Abstract
Small molecule natural products are a chemically diverse class of biomolecules that fulfill myriad biological functions, including autoregulation, communication with microbial neighbors and the host, interference competition, nutrient acquisition, and resistance to oxidative stress. Human commensal bacteria are increasingly recognized as a potential source of new natural products, which may provide insight into the molecular ecology of many different human body sites as well as novel scaffolds for therapeutic development. Here, we review the scientific literature on natural products derived from residents of the human nasal/oral cavity, discuss their discovery, biosynthesis, and ecological roles, and identify key questions in the study of these compounds.
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Affiliation(s)
- Colin Charles Barber
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley 94720, USA
| | - Wenjun Zhang
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley 94720, USA.,Chan-Zuckerberg Biohub, San Francisco 94158, USA
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Delftia acidovorans secretes substances that inhibit the growth of Staphylococcus epidermidis through TCA cycle-triggered ROS production. PLoS One 2021; 16:e0253618. [PMID: 34214099 PMCID: PMC8253425 DOI: 10.1371/journal.pone.0253618] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 06/08/2021] [Indexed: 12/22/2022] Open
Abstract
The proportion of Staphylococcus aureus in the skin microbiome is associated with the severity of inflammation in the skin disease atopic dermatitis. Staphylococcus epidermidis, a commensal skin bacterium, inhibits the growth of S. aureus in the skin. Therefore, the balance between S. epidermidis and S. aureus in the skin microbiome is important for maintaining healthy skin. In the present study, we demonstrated that the heat-treated culture supernatant of Delftia acidovorans, a member of the skin microbiome, inhibits the growth of S. epidermidis, but not that of S. aureus. Comprehensive gene expression analysis by RNA sequencing revealed that culture supernatant of D. acidovorans increased the expression of genes related to glycolysis and the tricarboxylic acid cycle (TCA) cycle in S. epidermidis. Malonate, an inhibitor of succinate dehydrogenase in the TCA cycle, suppressed the inhibitory effect of the heat-treated culture supernatant of D. acidovorans on the growth of S. epidermidis. Reactive oxygen species production in S. epidermidis was induced by the heat-treated culture supernatant of D. acidovorans and suppressed by malonate. Further, the inhibitory effect of the heat-treated culture supernatant of D. acidovorans on the growth of S. epidermidis was suppressed by N-acetyl-L-cysteine, a free radical scavenger. These findings suggest that heat-resistant substances secreted by D. acidovorans inhibit the growth of S. epidermidis by inducing the production of reactive oxygen species via the TCA cycle.
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11
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Dissecting Disease-Suppressive Rhizosphere Microbiomes by Functional Amplicon Sequencing and 10× Metagenomics. mSystems 2021; 6:e0111620. [PMID: 34100635 PMCID: PMC8269251 DOI: 10.1128/msystems.01116-20] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Disease-suppressive soils protect plants against soilborne fungal pathogens that would otherwise cause root infections. Soil suppressiveness is, in most cases, mediated by the antagonistic activity of the microbial community associated with the plant roots. Considering the enormous taxonomic and functional diversity of the root-associated microbiome, identification of the microbial genera and mechanisms underlying this phenotype is challenging. One approach to unravel the underlying mechanisms is to identify metabolic pathways enriched in the disease-suppressive microbial community, in particular, pathways that harbor natural products with antifungal properties. An important class of these natural products includes peptides produced by nonribosomal peptide synthetases (NRPSs). Here, we applied functional amplicon sequencing of NRPS-associated adenylation domains (A domains) to a collection of eight soils that are suppressive or nonsuppressive (i.e., conducive) to Fusarium culmorum, a fungal root pathogen of wheat. To identify functional elements in the root-associated bacterial community, we developed an open-source pipeline, referred to as dom2BGC, for amplicon annotation and putative gene cluster reconstruction through analyzing A domain co-occurrence across samples. We applied this pipeline to rhizosphere communities from four disease-suppressive and four conducive soils and found significant similarities in NRPS repertoires between suppressive soils. Specifically, several siderophore biosynthetic gene clusters were consistently associated with suppressive soils, hinting at competition for iron as a potential mechanism of suppression. Finally, to validate dom2BGC and to allow more unbiased functional metagenomics, we performed 10× metagenomic sequencing of one suppressive soil, leading to the identification of multiple gene clusters potentially associated with the disease-suppressive phenotype. IMPORTANCE Soil-borne plant-pathogenic fungi continue to be a major threat to agriculture and horticulture. The genus Fusarium in particular is one of the most devastating groups of soilborne fungal pathogens for a wide range of crops. Our approach to develop novel sustainable strategies to control this fungal root pathogen is to explore and exploit an effective, yet poorly understood naturally occurring protection, i.e., disease-suppressive soils. After screening 28 agricultural soils, we recently identified four soils that were suppressive to root disease of wheat caused by Fusarium culmorum. We also confirmed, via sterilization and transplantation, that the microbiomes of these soils play a significant role in the suppressive phenotype. By adopting nonribosomal peptide synthetase (NRPS) functional amplicon screening of suppressive and conducive soils, we here show how computationally driven comparative analysis of combined functional amplicon and metagenomic data can unravel putative mechanisms underlying microbiome-associated plant phenotypes.
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12
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Wang K, Liu Q, Liu C, Geng L, Wang G, Zhang J, Shu C. Dominant egg surface bacteria of Holotrichia oblita (Coleoptera: Scarabaeidae) inhibit the multiplication of Bacillus thuringiensis and Beauveria bassiana. Sci Rep 2021; 11:9499. [PMID: 33947948 PMCID: PMC8096819 DOI: 10.1038/s41598-021-89009-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/13/2021] [Indexed: 02/01/2023] Open
Abstract
Holotrichia oblita (Coleoptera: Scarabaeidae) and some other scarab beetles are the main soil-dwelling pests in China. Bacillus thuringiensis (Bt) and Beauveria bassiana (Bb) are entomopathogens that have been used as biocontrol agents of various pests. However, scarab larvae especially H. oblita exhibited strong adaptability to these pathogens. Compared to other scarabs, H. oblita could form a specific soil egg case (SEC) structure surrounding its eggs, and young larvae complete the initial development process inside this structure. In this study, we investigated the role of SEC structure and microorganisms from SEC and egg surface in pathogen adaptability. 16S rRNA gene analysis revealed low bacterial richness and high community unevenness in egg surface, with Proteobacteria, Firmicutes, Bacteroidetes and Fusobacteria dominating. In terms of OTUs composition analysis, the data show that the egg surface contains a large number of unique bacteria, indicating that the egg bacterial community may be derived from maternal transmission. Furthermore, we found that all culturable bacteria isolated from egg surface possessed antimicrobial activity against both Bt and Bb. The Pseudomonas bacteria with a significantly higher abundance in egg surface showed strong Bt- and Bb antagonistic ability. In conclusion, this study demonstrated a unique and antimicrobial bacterial community of H. oblita egg surface, which may contribute to its adaptability. Furthermore, the specific SEC structure surrounding the H. oblita eggs will provide a stable microenvironment for the eggs and egg surface bacteria, which probably provides more advantages for H. oblita adaptation ability.
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Affiliation(s)
- Kui Wang
- Guangdong Laboratory for Lingnan Modern Agriculture (Shenzhen Branch), Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China.,State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Qi Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Chunqin Liu
- Cangzhou Academy of Agricultural and Forestry Sciences, Cangzhou, 061001, China
| | - Lili Geng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Guirong Wang
- Guangdong Laboratory for Lingnan Modern Agriculture (Shenzhen Branch), Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China.,State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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Marian M, Fujikawa T, Shimizu M. Genome analysis provides insights into the biocontrol ability of Mitsuaria sp. strain TWR114. Arch Microbiol 2021; 203:3373-3388. [PMID: 33880605 DOI: 10.1007/s00203-021-02327-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 04/07/2021] [Accepted: 04/09/2021] [Indexed: 12/31/2022]
Abstract
Mitsuaria sp. TWR114 is a biocontrol agent against tomato bacterial wilt (TBW). We aimed to gain genomic insights relevant to the biocontrol mechanisms and colonization ability of this strain. The draft genome size was found to be 5,632,523 bp, with a GC content of 69.5%, assembled into 1144 scaffolds. Genome annotation predicted a total of 4675 protein coding sequences (CDSs), 914 pseudogenes, 49 transfer RNAs, 3 noncoding RNAs, and 2 ribosomal RNAs. Genome analysis identified multiple CDSs associated with various pathways for the metabolism and transport of amino acids and carbohydrates, motility and chemotactic capacities, protection against stresses (oxidative, antibiotic, and phage), production of secondary metabolites, peptidases, quorum-quenching enzymes, and indole-3-acetic acid, as well as protein secretion systems and their related appendages. The genome resource will extend our understanding of the genomic features related to TWR114's biocontrol and colonization abilities and facilitate its development as a new biopesticide against TBW.
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Affiliation(s)
- Malek Marian
- Faculty of Applied Biological Sciences, Gifu University, Gifu, 501-1193, Japan.,College of Agriculture, Ibaraki University, Ami, Inashiki, Ibaraki, 300-0393, Japan
| | - Takashi Fujikawa
- Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, 305-8605, Japan
| | - Masafumi Shimizu
- Faculty of Applied Biological Sciences, Gifu University, Gifu, 501-1193, Japan.
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Antibiotic Resistance Profiles, Molecular Mechanisms and Innovative Treatment Strategies of Acinetobacter baumannii. Microorganisms 2020; 8:microorganisms8060935. [PMID: 32575913 PMCID: PMC7355832 DOI: 10.3390/microorganisms8060935] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/19/2020] [Accepted: 06/19/2020] [Indexed: 12/18/2022] Open
Abstract
Antibiotic resistance is one of the biggest challenges for the clinical sector and industry, environment and societal development. One of the most important pathogens responsible for severe nosocomial infections is Acinetobacter baumannii, a Gram-negative bacterium from the Moraxellaceae family, due to its various resistance mechanisms, such as the β-lactamases production, efflux pumps, decreased membrane permeability and altered target site of the antibiotic. The enormous adaptive capacity of A. baumannii and the acquisition and transfer of antibiotic resistance determinants contribute to the ineffectiveness of most current therapeutic strategies, including last-line or combined antibiotic therapy. In this review, we will present an update of the antibiotic resistance profiles and underlying mechanisms in A. baumannii and the current progress in developing innovative strategies for combating multidrug-resistant A. baumannii (MDRAB) infections.
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